If this is all true, particles that collided at energies beyond this graviton-leaking energy cutoff would get so close together that gravity would take over, and they would merge to form a tiny black hole. The black holes would instantly decay, so there would be no danger of Earth being swallowed whole, and the decay would be visible as jets of particles. But the researchers have so far seen no jets.

And what was the prior likelihood that we would get beyond the energies required for this phenomenon to show up? What was known about this energy? Are the results we found consistent with what we know about this energy? What does the lack of jets tell us about this energy?

The point? This is quite far from being a knock-out blow to string theory. At worst it shows that the energies required for some effects are higher than what we can currently produce.

Never the less the point is valid by using simple calculation of wing area and muscle rates the bee can't fly. That is where this story stems from, and it took observation and explanation to explain it. I never made the claim science proved a bee can't fly, as in your legend .

I skipped to how science investigation explained how it can.

The same is true for the hummingbird , by wing area and known muscle rates , on paper can't fly and hover.

<quoted text>Never the less the point is valid by using simple calculation of wing area and muscle rates the bee can't fly. That is where this story stems from, and it took observation and explanation to explain it. I never made the claim science proved a bee can't fly, as in your legend .I skipped to how science investigation explained how it can.The same is true for the hummingbird , by wing area and known muscle rates , on paper can't fly and hover.http://www.popsci.com/scitech/article/2008-03...Also the distance a flea can jump is impossible by ordinary legs, but investigation showed how it is able.This is the point I was making.

I understand that. But I would guess that the details are lost on some of the people in the forum. ;)

<quoted text>It should also be pointed out that the fact that *one model* was unable to calculate the lift produced by a bee's wings did not mean that model was thrown out for everything else. The model assumed a flat, rigid, unmovable wing. That isn't how a bee's wings work. But that model works perfectly well for aircraft wings.So this is a small case where the theory was NOT 'thrown out' because the observations didn't support it. Instead, the assumptions of the model were modified to better model the actual situation.This is relevant for other situations also. For example, string theory has many adjustable parameters: the mass of the least massive supersymmetric particle, for example. Many of those parameters are constrained by observations we have already made, but often they are still allowed to have rather broad ranges. So, the predictions made from *one* set of parameters can differ from the predictions made from a *different* set of parameters. Now, if observations show the first set is wrong or unlikely, that does not disprove the whole theory--the second set could still be allowed.So, when TAT likes to quote that any defect in a theory requires it to be thrown out or modified, he doesn't seem to get that modifications can be as simple as different parameter values. To get to the place that a theory has to actually be thrown out, we need a prediction that holds for ALL allowed parameter values and that is contradicted by observation. This does happen, but is has not happened for string theory.

Not sure how you jump from the bee to string theory, I haven't said anything about that. I know it failed the first test but one test doesn't mean anything, except the test failed.How many tests failed to produce the Higgs Boson?If we believed a thousand tests before the one, it would be a failed hypothesis also right? What you are saying about string theory is exactly what I was saying about GR and BH's, except the only difference is the tests that confirm GR are many, the one or two it fails won't scrap the theory, but requires more explanation.

With string theory more on par with the Higgs with more failures than successful tests, but persistent testing finally produced a positive result. The same may be true for strings or supersymmetric strings. The same thing applies though , that it won't all be worked out on paper, because science requires thesephysical tests, and that was my whole point.

<quoted text>Not sure how you jump from the bee to string theory, I haven't said anything about that. I know it failed the first test but one test doesn't mean anything, except the test failed.How many tests failed to produce the Higgs Boson?If we believed a thousand tests before the one, it would be a failed hypothesis also right?

The tests that 'failed' to find the Higg's were more accurately tests that showed its mass was not in the ranges we tested. The problem was that the operative theory did not constrain the Higg's mass very well, so a fairly large range of masses was consistent with the theory. The observations narrowed the range over time until we were able to check in the right place and then we found it.

What you are saying about string theory is exactly what I was saying about GR and BH's, except the only difference is thetests that confirm GR are many, the one or two it fails won't scrap the theory, but requires more explanation.With string theory more on par with the Higgs with more failures than successful tests, but persistent testing finally produced a positive result. The same may be true for strings or supersymmetric strings. The same thing applies though , that it won't all be worked out on paper, because science requires thesephysical tests, and that was my whole point.

Exactly. The math alone doesn't tell us how the real world actually works. The theories and ideas have to be tested by actual observations. This can be complicated when the theory has a wide range of parameter values consistent with it (for example, the masses of the planets are not determined by Newton's laws) or when we have to simplify the assumptions in order to do the calculations. A 'failure' in these cases may simply mean we are in the wrong region of parameter space or that our simplifying assumptions were wrong. Unfortunately, we often cannot do the calculations unless there are such simplifying assumptions.

Of course, if you apply helicopter simulations to bees? They are reasonably worked out helicopters-- not as efficient as an engineered one, but what else from a directed-random process? It's good enough for the bees...

A 'failure' in these cases may simply mean we are in the wrong region of parameter space or that our simplifying assumptions were wrong. Unfortunately, we often cannot do the calculations unless there are such simplifying assumptions.

Instead of simplifying assumptions, wouldn't it be more productive to drop the assumptions and start over with a clean slate? It seems logical that if you're working with the wrong parameters it would be more productive to back up and start over. Would this approach work?

<quoted text>Instead of simplifying assumptions, wouldn't it be more productive to drop the assumptions and start over with a clean slate? It seems logical that if you're working with the wrong parameters it would be more productive to back up and start over. Would this approach work?

Yes in fact we do...Every single time. Do you have new figures to serve as a base lines?Or will we calculate the same things again? BTW you will have to explain what substantiates any "new" figures.

<quoted text> Yes in fact we do...Every single time. Do you have new figures to serve as a base lines?Or will we calculate the same things again? BTW you will have to explain what substantiates any "new" figures.http://www.youtube.com/watch?v =VegvworoMX4XX

Well the reason I asked is to determine if starting over is the correct approach to any field or discipline in which prior assumptions don't pan out. I would think this is only logical in all areas of study. Right?

<quoted text>Well the reason I asked is to determine if starting over is the correct approach to any field or discipline in which prior assumptions don't pan out. I would think this is only logical in all areas of study. Right?

<quoted text>You do realize that before the LHC started, the vast majority of string theorists predicted that no black holes would be found this way, right? That the conditions required under string theory for this to happen we understood *before* hand to be very unlikely in the LHC?

"According to the well-established properties of gravity, described by EinsteinÂs relativity, it is impossible for microscopic black holes to be produced at the LHC. There are, however, some speculative theories that predict the production of such particles at the LHC. All these theories predict that these particles would disintegrate immediately. Black holes, therefore, would have no time to start accreting matter and to cause macroscopic effects."

Notice that the theories that predict micro black holes were classified as *speculative*. Typically, in contexts like this, this means nobody really thinks it will happen.

<quoted text>Well, that's *one* scenario where you could get information from the event horizon. The other is to be lucky and actually watch something falling into a known black hole. That seems like an easier way, although the quality of the data might not be as good.

We've already seen stars fall into the black hole at the center of the Milky Way. Did you miss that nova program!

<quoted text>And what was the prior likelihood that we would get beyond the energies required for this phenomenon to show up? What was known about this energy? Are the results we found consistent with what we know about this energy? What does the lack of jets tell us about this energy?

The point? This is quite far from being a knock-out blow to string theory. At worst it shows that the energies required for some effects are higher than what we can currently produce.

46 years of zippo out of string theory. Hang in there it's bound to produce something useful.

<quoted text>Never the less the point is valid by using simple calculation of wing area and muscle rates the bee can't fly. That is where this story stems from, and it took observation and explanation to explain it. I never made the claim science proved a bee can't fly, as in your legend .

I skipped to how science investigation explained how it can.

The same is true for the hummingbird , by wing area and known muscle rates , on paper can't fly and hover.

<quoted text>Not sure how you jump from the bee to string theory, I haven't said anything about that. I know it failed the first test but one test doesn't mean anything, except the test failed.How many tests failed to produce the Higgs Boson?If we believed a thousand tests before the one, it would be a failed hypothesis also right? What you are saying about string theory is exactly what I was saying about GR and BH's, except the only difference is the tests that confirm GR are many, the one or two it fails won't scrap the theory, but requires more explanation.

With string theory more on par with the Higgs with more failures than successful tests, but persistent testing finally produced a positive result. The same may be true for strings or supersymmetric strings. The same thing applies though , that it won't all be worked out on paper, because science requires thesephysical tests, and that was my whole point.

"I know it failed the first test but one test doesn't mean anything, except the test failed."

Wikipedia:If anyone finds a case where all or part of a scientific theory is false, then that theory is either changed or thrown out.

A scientific theory in one branch of science must hold true in all of the other branches of science.

<quoted text>Well the reason I asked is to determine if starting over is the correct approach to any field or discipline in which prior assumptions don't pan out. I would think this is only logical in all areas of study. Right?

Think of all the wasted careers, all the money sunk into a wrong guess. Science could never admit they hit a dead end and string theory was a wrong road.

<quoted text>Instead of simplifying assumptions, wouldn't it be more productive to drop the assumptions and start over with a clean slate? It seems logical that if you're working with the wrong parameters it would be more productive to back up and start over. Would this approach work?

Unfortunately, there are *always* simplifying assumptions.

For example, when you are doing a chemical analysis of DNA in a lab, you tend to ignore the vibrations from the traffic on the highway nearby. That is a simplifying assumption. It turns out that when physicists are looking for certain other effects, that traffic vibration can be a *major* issue and hence cannot be ignored. It all depends on what you are looking at and how accurate you want to be.

Added to the physical simplifying assumptions, it is also the case that doing the *mathematical* calculations can be prohibitively difficult. So, in quantum electrodynamics, most formulas give the desired results as an infinite series. That means that a *perfect* mathematical analysis would take infinitely long using the techniques we have now. In practice, we take enough terms that we *think* the remaining terms don't have a significant effect on the answer. Very seldom, though, is it mathematically proven that this is the case. So even the mathematical calculation turns out to be an approximation.

To make matters worse, the fewer physical assumptions you make (by taking into account the traffic, for example), the harder the mathematical calculations are to do.

So, even if you have the correct theory with all the correct parameters, it can be very difficult to make a good prediction. it is possible, but typically not easy.

Now, add into this issues like the fact that we don't *know* whether a given theory is true or not (that's what we are trying to find out!) and that most theories have 'inputs' that are required to do the calculations at all. These might be things like the masses of the quarks, or, more significantly, of the Higg's boson. Often the values of these inputs are not known ahead of time (again, that's something we're trying to find out!).

So, what happens is that the calculations are done for a range of values of the unknown masses, under the simplifying assumption that we can ignore the tidal effects of the moon (usually, that is), and compared to noisy data obtained from actual observations.

In practice, there isn't a single 'slate' that people are working from. There are multiple slates with different assumptions for each theory and there are typically several competing theories. So, out of 50 'slates' that are actively considered at any time, each new batch of data eliminates (we hope) 5 or 10. On the other side, theorists are do calculations with more terms, or under different values for the masses, or coming up with entirely new theories.

<quoted text>Instead of simplifying assumptions, wouldn't it be more productive to drop the assumptions and start over with a clean slate? It seems logical that if you're working with the wrong parameters it would be more productive to back up and start over. Would this approach work?

Sometimes it's just a matter of plugging in the new parameters into the same equation. Other times, the whole calculation needs to be done again. And sometimes the whole edifice must be changed.

We seldom go all the way back to Aristotle when re-thinking particle physics. Instead, we tend to use certain methods that have worked well in a wide variety of situations, looking for new models with additional features.

The problem with starting over *completely* is that it ignores the information we have already learned from previous observations. It is also not nearly as easy as you might think to create a theory that is consistent with everything we know *and* is completely new. Remember that the difference between the prediction of Newton's model of gravity and Einstein's model of gravity was 43 seconds of arc *per century* in the orbit of Mercury. But that was enough to overthrow Newton. THAT is the level of accuracy that was required 100 years ago. it is more now.

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